AMD Radeon 780M vs NVIDIA GeForce GTX 670MX

AMD Radeon 780M

The AMD Radeon 780M is an integrated GPU in the Ryzen 7040 series for laptops (Phoenix, e.g. Ryzen 9 7940HS). The iGPU is based on the new RDNA3 architecture and has 12 CUs (= 768 shaders) clocked at up to 3 GHz (depending on the CPU model). As the predecessor Radeon 680M, the 780M supports hardware raytracing, although the performance is too slow to use it in current games.

Thanks to the new architecture and higher clock speeds, the Radeon 780M should be clearly faster then the old Radeon 680M. This means most demanding games should be playable in minimum graphics settings (like Cyberpunk 2077) and less demanding games like Fifa 23 can be played in higher settings and resolutions (1080p). In early 2023, the Radeon 780M is the fastest iGPU on the market.

Thanks to the modern 4nm process and clever power-saving features, the power consumption is comparatively low (according to AMD). The whole chip of the first two models can be configured between 15 - 54 Watt TDP.

NVIDIA GeForce GTX 670MX

The NVIDIA GeForce GTX 670MX is a high-end DirectX 11-compatible graphics card for laptops. As opposed to the Fermi-based GTX 670M, the 670MX uses a newer 28nm GK106 core based on the Kepler architecture, similar in structure to the GTX 675MX and 680M. Compared to the slightly faster GTX 675MX, the 670MX offers a narrower memory bandwidth of 67.2 GB/s (vs. 115.2 GB/s of the 675MX) due to both slower memory modules and a smaller 192-bit bus width.

Architecture

The Kepler architecture is the successor to the Fermi architecture that first appeared in laptops with the GeForce 400M series. The GK106 Kepler core offers five shader blocks, called SMX, that are clocked at the same speed as the central core. In the GTX 670MX, all five blocks are active for a total of 960 CUDA cores. Although the Kepler architecture can utilize more shader cores than a Fermi chip, its shaders can be up to twice as power efficient.  However, due to the missing hot clock of the shader domain, two shaders of a Kepler chip are of similar speed to one shader of a Fermi chip (as the latter is clocked twice as fast).

PCIe 3.0 is now supported by the mobile Kepler series and an optional Turbo mode can automatically overclock the Nvidia card by a theoretical 15 percent if the laptop cooling system allows it. The implementation of this boost mode is done in the BIOS, but it is ultimately dependent upon the manufacturer of the laptop.

Performance

The graphics performance of the GeForce GTX 670MX is clearly above the older GTX 670M and therefore in the high-end class of mobile graphics cards of 2012. Only the extremely demanding title The Witcher 2 may not run fluently in ultra settings. Battlefield 3, Skyrim, and Crysis 2, for example, are playable at the highest detail settings.

Features

The improved feature set now includes support for up to 4 active displays. Furthermore, high resolution monitors of up to 3840x2160 pixels can now be connected using DisplayPort 1.2 or HDMI 1.4a if available. HD-Audio codecs, such as Dolby TrueHD and DTS-HD, can be transmitted via bitstream mode through the HDMI port. However, as most laptops will feature Optimus, the integrated GPU will likely have direct control over the display ports and may limit the feature set available by the Nvidia Kepler cards.

The 5th generation PureVideo HD video processor (VP5) is also integrated in the GK104 core and offers hardware decoding of HD videos. Common codecs such as MPEG-1/2, MPEG-4 ASP, H.264 and VC1/WMV9 are fully supported up to 4K resolutions while VC1 and MPEG-4 are supported up to 1080p. Two streams can be decoded in parallel for features such as Picture-in-Picture. Another novelty is the inclusion of a dedicated video encoding engine similar to Intel QuickSync that can be accessed by the NVENC API.

The power consumption of the GeForce GTX 670MX should be similar to the GTX 670M and is therefore best suited for large notebooks (17-inches or greater) and desktop replacements.